The 33 rescued Chilean miners have undergone extensive medical checks since being hauled to the surface, but doctors believe that most of them are in surprisingly good health after their two-month ordeal.

At least one of the men is believed to have suffered a perforated eardrum in the catastrophic rockfall which sealed the San José mine, and may require surgery. Another is being treated for pneumonia, but the most common complaint among the men is toothache.

One man, Osmán Araya, was in so much pain from an infected tooth that, for the last few nights in the mine, he was told to sleep sitting up and take painkillers. For Araya, surgery is almost certainly necessary, according to a nurse who had access to his medical files.

John Milne, chair of the General Dental Practice Committee of the British Dental Association, said the miners' dental problems probably stem from the first 17 days of their incarceration, during which they survived on sips of water and small amounts of tuna fish.

"If they couldn't brush their teeth properly for that length of time then they would have got a build up of plaque and bacteria," said Milne.

"And if they weren't eating fruit and vegetables, then they won't have been getting vitamin C. They would probably have had an acute infection of the gums, which is very painful."

Minor dental problems can easily be treated, but the men's most enduring problems may be emotional.

"There should be concern about their psychological adjustment over time, particularly after the joy of the reunion period, which will last for a few days to a few weeks," said John Fairbank, a professor of psychiatry at Duke University medical centre.

At times Sánchez was so disoriented that he saw visions of his mother who he thought had come to visit him in the mine, bringing him food and comfort.

The youngest member of the 33 is expected to have extensive post-trauma counselling, and will be among the most closely monitored of the rescued men.

By contrast the miner who survived in the best condition is Edison Peña, an exercise enthusiast who chopped down his mining boots to turn them into makeshift running shoes, bruising his feet yet still running up to six miles a day through the darkened tunnels.

Peña's exercise regime was so extensive that medical authorities sought to slow him down by lowering his calorie intake – an unsuccessful effort to reign in the hyperactive man.

One of the most visible effects of the 70-day subterranean saga has been the men's pale skin caused by prolonged time spent in the dark.

Since emerging from the mine, most of them have worn sunglasses at all times. Geoff Roberson, a qualified optometrist and professional adviser to the Association of Optometrists, said the light outside the mine could be "a thousand times brighter" than what the men had experienced over the past two months.

"Ultraviolet light is a hazard as far as the eyes are concerned," he said. "If they are very adapted to a dark environment then are going out into a place where UV light levels are quite high, then with very dilated pupils they could suffer longer term damage as a result of excessive ultraviolet light exposure."

The good news for the miners is that Roberson would be "very surprised" if they suffered longer term damage as a result of their ordeal, and the men could expose their eyes to sunlight over the next few days.

Exposure of a rather different kind has come sooner for Oakley, the manufacturer and donator of the sunglasses. Yesterday a US analytics company estimated the product placement could be worth $41m to the firm, given the global coverage of the miners' rescue.